Photoshop filling up space when in use

Problem

When using Photoshop, you get messages saying you have low disk space and reporting that the scratch disk is full.

Solution

You can change the drive that Photoshop uses its temporary files on by going to:

1. Click Edit (on the top menu).
2. Go to Preferences -> Performance.
3. Where it says Scratch disks, uncheck the drive with low space and tick a drive that is more suitable.
   This is useful if your hard drive is partitioned or have another hard drive present. It would not be advisable to use an external hard drive.